Baasha son of Ahijah, from the tribe of Issachar, conspired against Nadab ¹  and assassinated him in Gibbethon, which was in Philistine territory. This happened while Nadab and all the Israelite army were besieging Gibbethon.

His servant Zimri, a commander of half of his chariot force, conspired against him. While Elah was drinking heavily ¹  at the house of Arza, who supervised the palace in Tirzah,

The rest of the events of Zimri’s reign, including the details of his revolt, are recorded in the scroll called the Annals of the Kings of Israel. ¹ 

While deployed there, the army received this report: ¹  “Zimri has conspired against the king and assassinated him.” ²  So all Israel made Omri, the commander of the army, king over Israel that very day in the camp.